Isolation and identification of bioactive compounds of Burkholderia HQB-1 strain inhibiting banana wilt

Abstract:

[Background] Burkholderia HQB-1 has good control effect on banana fusarium wilt (Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4)). [Objective] The active compound was separated from the fermentation broth of HQB-1 strain, and the active compound was detected by HPLC-MS to obtain the monomer compound with good biocontrol effect. [Methods] HQB-1 strain was fermented in large quantities, and then the fermentation broth was separated and purified. The active compounds were identified by HPLC-MS and NMR. [Results] The protein from fermentation broth of HQB-1 strain had no inhibitory effect on Foc TR4. The catechol type iron carrier rather than hydroxamic acid type iron carrier was produced from HQB-1 strain. HQB-1 strain fermentation broth was centrifuged, concentrated and dried to obtain ethyl acetate extract (crude extract), which was then fully adsorbed by macroporous resin column. The components 1?3 were obtained after eluting by 30%, 60% and anhydrous methanol, and the corresponding inhibitory rate to Foc TR4 was 10.06%, 27.82% and 51.40% respectively. The component with the highest inhibitory rate was selected, and the yellow green crystal was obtained through silica gel column chromatography. The compound had a maximum absorption peak at 365 nm wavelength. The antibacterial activity compound was identified as phenazine-1-carboxylic acid (PCA), after the comparative analysis of NMR spectrum with SciFinder and SDBS information database. The minimum inhibitory concentration (MIC) of PCA to Foc TR4 was the lowest, only 1.563 μg/mL, indicating that PCA had a strong inhibitory effect on Foc TR4. [Conclusion] The active compound PCA isolated from HQB-1 strain had the biocontrol effect on banana fusarium wilt.